Electromagnetic Spectrum:

Different kinds of electromagnetic waves can be classified by their
wavelengths. They are classified into sections called bands. The
electromagnetic spectrum is the collection of these bands. The following
types of waves make up the electromagnetic spectrum: gamma rays, x-rays,
ultraviolet rays, visible light, infrared waves, and radio waves. The
length of these waves ranges from 10-12 metres to 102
metres long; this is known as the wavelength.